Apparatus for forming hollow bodies



Feb. 13, 1945. s v gsc 2,369,608

APPARATUS FOR FORMING HOLLOW BODIES Filed Jan. 16, 1940 2 Sheets-Sheet l1322:: Fw wlsl V 21 4 Inventor Feb. 13, 1945. P. SALVANESCHI 2,369,608

APPARATUS FOR FORMING HOLLOW BODIES Filed Jan. 16, 1940 2 Sheets-Sheet 2[72 2/672 for P/NO \S/4LV/4/VESCH/ Patented Feb. 13, 1945 APPARATUS FORFORMING HOLLOW BODIES Pino Salvaneschi, Broni, Italy; vested in theAlien Property Custodian Application January 16, 1940, Serial No.314,030 In Germany February 18, 1939 13 Claims.

Processes for manufacturing pipes with or without sockets, of cementpaste which may contain fibrous matter, are well known. In many suchprocesses a wrapping drum or cylinder is provided on which the pipe isformed in successive compressed layers. The speed of the wrapping drumin many of the above-mentioned processes depends on the speed of a feltband, of a ribbon, or of a roller.

Therefore, when a pipe having asocket is being wrapped, the angularspeeds of the contacting rollers, or the linear speed of the felt bandor ribbon, cannot be constant for the whole of the pipe length, sincethese speeds must be proportional to the various diameters of the pipe.In other words, the socket portion usually is of a greater diameter thanthe remaining portion of the pipe and, therefore, the speed of thefeltband or ribbon must be varied accordingly.

Consequently, whatever mechanical device is adopted, the portion of thepipe disposed between the small and large diameters is always a regionof least structural resistance and of least impermeability, and thetools required are always complex and expensive. The same may be saidconcerning the compression, simultaneous or subsequent to the shaping ofthe pipe. There is an additional disadvantage during the compression onaccount of the'pipe pressure requiring heavy tools to avoid fienuralstresses. These high pressures, however, are sometimes partially reducedby mechanical means.

The weight of the parts in motion and the inherent friction cause, ingeneral, the whole compression system to be insensitive in itsoperation.

Other processes for manufacturing pipes from fibrous pastes are alsoknown, whereby a rotatable supporting cylinder having holes therein isemployed. The cylinder and holes are covered by a filtering fabric andthe fabric is smeared or covered with a given thickness of paste, theinside of said cylinder being subjected to a reduced pressure or suctionfor draining the water from the applied paste in a manner practiced inthe operation of any drum-filter. (See, for instance. Die Asbest-ZementSchlefer Fabrication-a practical handbook-by K. A. Weniger, M. Krajneditors, Berlin, 1926,- from page 160 to page 164). In these processes,however, the condensing and compression of the material are limited.

The present invention is characterized by the feature that the kneadedpaste, whatever beits nature. is deposited upon a vibrating oroscillating table. This table is preferably inclined with movement at acertain distance toward and away from a revolving cylinder, whichcylinder is formed from porous or permeable material. A reduced pressureor suction may be maintained within the porous or permeable cylinder,and the paste is thrown against the cylinder and deposited on it by thevibrating or oscillating table. The angular speed of the cylinder uponwhich the paste is applied, is independent of the speed of the othermembers of the apparatus, regardless of the diameter or diameters of thepipe.

The other distinguishing features of the present invention will bedisclosed in the specification with the help of the attached drawingswhich are intended to give purely an example of an embodiment which islikely to vary in practice in its details, without thereby exceeding thelimits of the present invention.

In said drawings:

Figure 1 is a longitudinal section of the apparatus, taken along theline 11-! in Figure 2;

Figure 2 is a sectional plan view taken along line 2-2 in Figure l, butomitting portions of the feed hopper;

Figure 3 is an enlarged transverse sectional view, with the centralportion thereof broken away, said view being taken along lines 33 inFigures 1 and 2;

Figure 4 is a sectional view illustrating a modified form of feedhopper;

Figure 5 is a sectional view illustrating a modified form of tableconstruction in association with the revolving cylinder upon which thepipe is formed.

Referring more particularly to the drawings, the numeral I designates ahollow perforated cylinder or drum over which paste 2a is strewn ordeposited to form a pipe 2, said cylinder having trunnions 3 and 3'which are removably and rotatably supported in U-shaped notches Na inside frames 2!. An inclined vibrating or oscillating table 4 is disposedbetween side frames 2|, the lower end of said table being supported byeccentrics l0 and its upper end being pivotally connected to the upperends of suitable links [5 as at; points 5. The lower ends of links 6 aremounted around rotating eccentrics 8 which are fixedly secured upon ashaft 1. Likewise, the eccentrics l0 are fixedly secured'upon a shaft H.

The eccentrics H) on shaft I I may be turned gradually during operationfor adjusting or varying the degree of rapid oscillation of the upperrespect t a horizontal plane and mounted for 5 end of the table, saidrapid oscillation being sisame time a slower or gradual motion isimparted to the lower portion of the table in the direction C-D and DCwhen the shaft II and eccentrics ID are turned. There is also a longitwdinal motion imparted by the eccentrics to the table.

As stated above, the lower end of the table 4 is supported by eccentricsIII, and, therefore, upon gradually revolving the eccentric in aclockwise direction from the position shown through an angle of 180, theinclined top surface of the table will be moved away'from the cylinderor drum I in a direction DC substantially normal to said surface, whileat the same time the upper end of the table is vibrating or oscillatingrapidly. The table will also be moved longitudinally downwardly in thedirection of incline during the first 90 rotation of eccentrics III andlongitudinally upwardly in the direction of incline during thesucceeding 90 rotation. Therefore, each oscilla-v tion of the tableresulting from eccentrics 8 will follow a slightly different path fromthe path of the preceding oscillation, on account ofthe gradual shiftingof the lower pivot point III. Of course, the relative rates of rotationof the respective eccentrics 8 and II) varies the frequency and thepaths of oscillation followed by the table. The shaft I at the upper endof the table structure is driven very-rapidly by any suitableconventional means such as disclosed in Figure 2. As an example of thedriving means, the upper shaft I has a sprocket 25 fixedly securedthereon upon which a chain 26 is mounted, said chain being also mountedupon a sprocket II of a speed reduction unit 28. The reduction unit isdriven by any suitable means such as an electricmotor 30 in aconventional manner.

The lower shaft I I is driven slowly or gradually in a similar manner bysprocket II, chain 32 and sprocket 33. Although, a common driving meansis employed for the upper and lower eccentrics 3 and II), a separatedriving means may be employed. It is evident-that good results may beobtained if the eccentrics I are manually rotated while the tableoscillates or vibrates. In the present showing the two pulleys 21 and 3|are geared so that pulley 21 will be driven very rapidly while pulley 3|is driven very slowly. In other words, the vibratory or oscillatingmotion is imparted to the upper end of the table 4 through members 5, 6,I, 8, 25 and 26 while the table is moved away from cylinder I by membersII), II, 3I, 32 and 33 to provide clearance for the paste 2a which isbeing deposited on the rotating cylinder I to form pipe 2. Usually, theentire amount of paste is deposited during the first 180 degreesrevolution of eccentrics III, and during the second and successive turnsof eccentrics III the pipe is compressed and consolidated. Although theentire amount of paste may be deposited upon the rotating cylinder ormandrel I during the first 180 of revolution of eccentric I 0, it shouldbe borne in mind that the mandrel may rotate several revolutions. Inother words, when the table is located in its uppermost position asshown in Fig. 1, there is a minimum space between the periphery of themandrel and the top of the table, and this minimum space issubstantially equal to the sheet of pasty substance 2:; which is beingapplied to the mandrel. After the mandrel has made substantially onerevolution, the eccentric III will .have turned downwardly a sufficientamount to plastic material will have formed on top of the first layer.In other words, when the mandrel is rotated a plurality of revolutionsduring the formation of the pipe, the plastic material will be appliedin the form of a spiral winding. At all times, the uppermost limit ofthe travel of the table approaches the periphery of the cylindersufficiently to compress the pasty substance which is being applied.

A fly wheel 8 is fixedly secured upon shaft 1 so that a greater momentumwill be maintained after the shaft has reached the operating speed.Since the table oscillates at a high rate, the shaft I must rotatecorrespondingly fast, and under such conditions it is sometimesnecessary to counter-balance the fiy-wheel as at 9a to balance thecentrifugal weight of the eccentrics 8 about rotating shaft I.

The proximate faces of side frames 2| have sides I9 and 20 extendinginwardly therefrom into close proximity to opposite edges of table 4, tothereby prevent the paste from falling from the sides of the table whenthe table is oscillating. The top surfaces of the side members I9 and 20are shaped in such a way as to closely approach, without touching, thelarge and small peripheries at each end of the cylinder I, theintermediate portion of said cylinder disposed between said sides" beingadapted to receive the paste 2a from the table 4. (See Figure 3) Theremovable cylinder I to which paste 2a is applied may be driven eitherin a continuous or a non-continuous way. A conventional continuousdriving means is shown, comprising a sprocket 35 fixedly mounted ontheend of trunnion 3', a sprocket chain 36, a second sprocket 31, a gearreduction unit 33 and a motor 33. It is evident that the rate ofrotation of cylinder I will be much slower in relation to the rate ofrotation of shaft I which operates to oscillate or vibrate the table sothat the paste can be properly deposited on the cylinder in successivelayers. v

The charging hopper is designated by reference character I2 wherein isdeposited the whole amount of paste 2a for obtaining a pipe of a givensize, said hopper having an opening 12a in the lower end thereof whichis substantially closed by table 4 when the link 6 is at the uppermostposition of its stroke.-

Upon rapidly oscillating the upper end of inclined table 4, the paste 2aintermittently falls out of the hopper onto the uppermost portion of thetable and is caused'to flow downwardly, with the assistance of gravitytoward revolving cylinder I. As the paste approaches the cylinder it isapplied thereto by the above-described oscillations to thereby form apipe 2. The lower end of the table is gradually moved away from thecylinder due to the rotation of shaft I I during the application of thepaste 2a and the formation of the pipe 2.

The drum or cylinder I is porous or permeable only in the part whichreceives the paste, said pores in the cylinder being indicated by Ia(Figure 3). Cylinder I is also provided with holes I3 and with a headI6, havin'gproiections II, integral therewith, said holes I3establishing communication between the interior of cylinder I and anannular space 40 in sleeve I8. The sleeve I8 siidably fits over thecylinder I in the manner shown in Figure 3. and when so positioned theannular space 40 establishes communication between holes I3 andpassageways I4 and IS, the passageway I! being disposed substantially inalinement with the axis of rotation of cylinder I.

' Attention is called to the perforations no in inserted into passagewayI5 and is connected to the cylinder by any suitable means such asasealed ball bearing 43. A suction pump 44 is connected to the other endof the conduit, and a valve 45 is employed in the conduit to regulatethe amount of suction produced.

The excess water in the paste 2a filters through the pores Ia into thecylinder I and is discharged therefrom through openings I3, 4|], I4, I5and into suction conduit 42, as a result of the suction means.

The operation is as follows:

The required paste id for a given pipe 2 is placed in hopper I2, afterhaving set the vibrating or oscillating table at its top-dead-center soas to close or reduce the opening I2a. The eccentric I0 is also set inthe position shown so as to reduce the space between cylinder I andtable 4 to the desired minimum. The upper portion of the table is thenset in motion due to the rapid rotation of drive shaft I, and the pasteflows with the aid of gravity from opening I2a towards the cylinder I.At the proper moment the cylinder I is rotated and also the vacuum orsuction apparatus is placed in operation. A slower rate of rotation issimultaneously imparted to the lower shaft II and eccentrics III togradually move the table downwardly from the cylinder to give space forthe pipe thickness, during which downward move ment the contents of thehopper are deposited upon cylinder I.

If the vibro-compression, produced by the vibrating or .oscillatingtable 4 upon the pipe during its formation, is not considered sumcient,the operation of cylinder I and table 4 is continued to thus consolidatethe pipe.

As soon as the pipe is considered finished, after the above-statedoperations, it is possible to go on with the vibro-compressing, i. e. bycontinuing the oscillation of the table, and if desired the suctionwithin cylinder I may be reduced so as to insure that the inside surfaceof the finished pipe may separate'from the outside surface of thecylinder.

When the formation of the pipe is completed,

the cylinder I is disconnected from conduit 42 and from driving chain36, after which the cylinder and finished pipe is removed from notches 2la. The pipe is then slipped from the cylinder by pushing the sleeve I8toward trunnion 3', or by holding the sleeve and then extracting thecylinder. Also the pipe may be removed by placing both the pipe andcylinder in upright position and dropping the cylinder and sleeveendwise on the floor so as to leave the pipe vertical.

In the practical embodiment of the process, the oscillations may be verydifferent in nature, frequency, direction, and amplitude. In theapparatus shown in Figures 1 and 2, as an example, the oscillations arein the direction A-B, B-A, and are gradually damped toward the lower endof the table. These oscillations may be replaced by others, whatever bethe'kinematic or dynamic 1 law they are obeying, and whatever be theratio between the oscillations at a certain point and those at any otherpoint of the vibrating table. As above stated, these oscillations may bevaried by rotation of the eccentric I0 about its axis I I.

Hopper I2, shown in Figure 1, may be replaced, if desired, by a dumpinghopper I2 such as shown in Figure 4, the hopper being adapted to rotateabout point 120.

It is not necessary to uniformly deposit the paste on the vibratingtable for the entire length of the pipe generatrix. The vibration of thetable provides for the application of the paste where required, that is,the spreading of the paste longitudinally of the cylinder.

The manufacture of the pipe may be obtained even in a single revolutionof the drum, in which case the initial distance or the air-gap betweenthe top of the table and the cylinder, when the table is in hold lineposition, as shown in Figure 5, establishes the thickness of thenon-compressed pipe (Figure 5). In such case the table 4 may be suitablyconcaved as at 4a so that a portion of the concavity will approximatelyconform to the body of the cylinder. Also in this embodiment, (Figure 5)since only one layer of paste is applied to form a pipe the eccentricIII at the lower end of .the table, should not turn because the spacebetween cylinders I and 8 the top of the table will remain constant. Thepressing and finishing of the formed pipe by means of vibro-compressionmay be obtained, whatever be the way the paste is applied over the drum.

Having now particularly described the nature of my invention and itsmanner of operation, I claim:

l. A machine for manufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprising in combination a rotatably mountedpermeable cylinder, said cylinder adapted to have suction meansconnected thereto for exhausting air from the inside of said cylinder;an inclined paste-applying member located near the surface of saidcylinder, means located near the upper end of said pasteapplying memberfor depositing a pasty substance upon said member, said member beingpivotally mounted for oscillation toward and away from said cylinder tothereby apply and compress said deposited pasty substance to saidcylinder as said cylinder rotates; and means for gradually moving saidtable pivot and associated oscillating table away from said cylinderwhile said paste is applied to thereby provide space for the appliedpaste on said cylinder.

2. A machine for manufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprising in combination a rotatably mountedpermeable cylinder, an inclined paste-applying mem-- ber located nearthe surface of said cylinder, means located near the upper end of saidpasteapplying member for depositing a pasty substance upon said member,said member being pivotally mounted for oscillationtoward and away fromsaid cylinder to thereby apply and compress said deposited pastysubstance to said cylinder as said cylinder rotates; and means forgradually moving said table pivot and associated oscillating table awayfrom said cylinder while said paste is applied to thereby provide spacefor the applied paste on said cylinder.

3. A machine for manufacturing tubes, pipes or similar hollow .bodiesfrom pasty substances comprising in combination a rotatably mountedpermeable cylinder adapted to have suction means connected thereto forexhausting air from the inside of said cylinder, an inclinedpaste-applying table having the top surface thereof located adjacent thelower surface of said cylinder; paste delivery means throttled face andlocated at a point above said adjacent table and cylinder surfaces; andmeans for vibrating said table toward (1 away from said delivery meansand toward and away from said cylinder to respectively facilitate thegravity flow of the pasty substance from the delivery means and tocompress the delivered paste upon said rotating cylinder.

4. A machine as defined in claim 3 wherein means are provided forgradually moving the top surface of said vibra table away from saidcylinder surface while said paste is applied to thereby correspondinglyincrease the thickness of the pipe being formed.

5. A machine as defined in claim 3 wherein means are providedforgradually increasing the distance between the top surface of saidvibrating table and the lower surface of said cylinder while said pasteis applied to thereby correspondingly increase the thickness of the pipebeing formed.

6. A machine as defined in claim 3 wherein said means for delivering thesupply of paste to the table comprises a hopper for holding said paste,said hopper having an outlet at its lower end disposed djacent the topsurface ofthe table.

7. A machine as defined in claim 2 wherein oscillating means areprovided for said table comprising an eccentrically mounted memberflxedupon a rotating shaft and a link pivotally connecting said eccentricallymounted member with said table.

8. A machine as defined in claim 2 wherein oscillating means areprovided for said table comprising an eccentrieally mounted member fixedupon a shaft and a link pivotally connectin said eccentrically mountedmember with the table, and wherein said means for moving said tablepivot comprises a second eccentric rotatably journaled in the table.

9. A machine for manufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprising in combination a rotatably mountedcylinder, an inclined paste-applying member having the top surfacethereof located adjacent the vlower surface of said cylinder, the upperportion of said top surface being adapted to have a mass of pastysubstances deposited thereon,

and means for vibrating said inclined member toward and away from saidcylinder, whereby the gravity flow of the deposited pas y substancesalong said top surface and the compression of said substance upon thecylinderrwill be facilitated.

10. A machine forrmanufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprising in combination a rotatably mountedcylinder, an inclined paste applving member having the top surfacethereof located adjacent the lower surface of said cylinder, the upperportion of said top surface being adapted to have a mass of pastysubstances deposited thereon,

lrlysaidtablesurpasty substance to said means forvlbratins said inclinedmember toward and away from said cylinder, whereby the gravity flow ofthe deposited pasty substances along said top surface and thecompression of. said substance upon the cylinder will be facilitated,and means for moving the top'surface of said inclined vibrating memberaway from the lower surface of said cylinder while the paste is beingapplied to the cylinder to thereby correspondingly increase thethickness of the pipe being formed.

11. A machine for manufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprisin in combination a rotatably mountedcylinder, an inclined paste-applying member having the top surfacethereof located adjacent the lower surface of said cylinder, the upperportion of said top surface being adapted to have a mass of pastysubstances deposited thereon, means for vibrating said inclined membertoward and away from said cylinder, whereby the gravity flow of thedeposited pasty'substances along said top surface and the compression ofsaid substance upon the cylinder will be facilitated, and means forincreasing the distance between the top surface of said vibrating memberand the lower surface of said cylinder while the paste is being appliedto the cylinder to thereby correspondingly increase the thickness of thepipe being formed.

12. A machine for manufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprising in combination a rotatably mountedpermeable cylinder, said cylinder adapted to have suction meansconnected thereto for exhausting air from the inside of said cylinder;an

inclined paste-applying member located near the surface of said cylinderwhereby pasty substances deposited upon the upper portion of said memberwill tend to move toward said cylinder, said member being pivotallymounted for oscillation toward and away from said cylinder to therebyapply said deposited pasty substances to said cylinder as said cylinderrotates; and means for gradually moving said table pivot and associatedoscillating table away from said cylinder while said paste is applied,to thereby provide space for the applied paste on said cylinder.

13. A machine for manufacturing tubes, pipes or similar hollow bodiesfrom pasty substances comprising in combination a rotatably mountedpermeable cylinder, an inclined paste-applying member located near thesurface of said cylinder whereby pasty substances deposited upon theupper portion of said member willtend to move toward said cylinder, saidmember being pivotally mounted for oscillation toward and. away fromsaid cylinder to thereby apply said deposited cylinder as said cylinderrotates; and means for gradually moving said table pivot and associatedoscillating table away from said cylinder while said paste is applied tothereby provide space for the applied paste on said cylinder.

PINO SALVANESCHI.

